Surgical dressing and method of producing the same



Dec. 9, 1969 w. SCHUSTER 3,482,570

SURGICAL DRESSING AND METHOD OF PRODUCING THE SAME Filed Jan. 18, I967Inventor 4%% W United States Patent T Int. Cl. A611 15/ 01; A61f 13/00US. Cl. 128-156 5 Claims ABSTRACT OF THE DISCLOSURE A surgical textiledressing consisting of one or more layers of non-woven fabric which isneedled vertically to its plane so that Wicklike fiber bundles extendthrough the fabric, and wherein the entry side of the needles into thefabric which engages with the wound is provided with a thin coating ofadhesive which connects the uppermost fibers but leaves intermediatespaces through which the moisture of the wound will be absorbed.

Background of the invention The present invention relates to a surgicaldressing of a textile material which is made of a non-woven fabric orfleece material.

The general requirements of a good textile dressing are that it behighly absorbent, have a sufficient capacity for absorbing secretions,and allow air to penetrate easily. Furthermore, it should rest on thewound without folds, be nonirritant, and not stick to or grow togetherwith the wound.

There is a known kind of surgical dressing which consists of a fabricwhich has the disadvantage that, due to its type, thread count, threadthickness, and degree of twist, some of its threads shrink differentlyfrom others when absorbing moisture. This causes the fabric to move ofits own accord and it contracts to a wavy condition. Although, if thereis only a slight secretion from the wound, this dressing will not stickto the wound, the wound will not be kept absolutely quiet and if astrong secretion occurs, the absorptive capacity of the dressing isoften insuflicient.

Another known kind of surgical dressing comprises a fleece material inwhich the gaps between the fibers are reduced by compression and thecontact surface of which is treated with aluminum by vapor-deposition inorder to prevent the dressing from sticking to the wound. A similareffect is supposed to be attained by another .kind of dressing whichconsists of a sheet of polypropylene into which numerous small holes arepunched and upon the upper side of which a wide-mesh gauze is glued.

Both of these surgical dressings have very little, if any, absorptiveproperties and therefore require an additional layer of an absorbentmaterial.

Summary of the invention It is an object of the present invention toprovide a surgical dressing of a textile material which complies withall of the requirements as outlined at the beginning and has aconsiderably higher absorptive capacity than the conventional dressingsand also a sufliciently smooth contact surface in order to prevent itfrom sticking to the wound.

According to the invention, this object is attained by needling thenon-woven fabric or fleece material and applying a thin coating ofadhesive upon the uppermost fiber layer on the entry side of the needleswhich is ap- 3,4825% Patented Dec. 9, 1969 ICC plied upon the wound soas to connect the fibers of this layer to each other.

Although by applying an adhesive upon the fibers of the uppermost fiberlayer of a non-woven fabric at the entry side of the needles, theseuppermost fibers will be connected to each other and thinly coated withthe adhesive, the funnellike recesses which are produced by the needlingoperation and the surfaces of which are located underneath the uppermostfibers will remain uncoated. The surgical dressing which is thusproduced therefore has a sufficiently smooth contact surface and sincethe fibers on this surface are firmly connected to each other, theycannot grow into the wound. Such a nonwoven fabric or fleece has thefurther advantage that, while having the same weight as a woven fabric,it has a much higher absorptive capacity. This is due to the fact thatin a needled fleece the individual fibers are spaced at practically thesame distance from each other and, contrary to a woven fabric, none ofthe gaps between the fibers are too large for accumulating moisturetherein. By the needling operation, a considerable number of the fibersof the fleece are bent and aligned in a direction substantially verticalto the longitudinal plane of the fleece and these fibers also extendvertically to the liquid level of the wound Which is covered by thedressing. Consequently, a Wicklike effect is produced by these verticalfibers which further increases the absortive capacity of the dressing.

Another feature of the invention consists in providing a supportingfabric within the needled fleece, for example, in the form of absorbentgauze. The combination of this supporting fabric with the needling ofthe non-woven fabric or fleece results in a relatively solid surgicaldressing of stable dimensions.

Recent investigations have shown that white and metalcoated surgicaldressings due to their high heat-reflecting capacity may cause anincrease in the wound temperature of more than 4 C., while aviolet-colored textile dressing of the same thickness only produces atemperature increase of about 0.6" C. In order to prevent such anundesirable increase in the wound temperature, the present inventionfurther provides that the adhesive is preferably died to aheat-absorbing color.

Aside from its object of attaining a new and improved type of surgicaldressing, the present invention is further directed to provide a methodof producing this dressing. This method consists of the steps ofneedling the nonwoven fabric or fleece and thereafter passing it througha pair of revolving coating rollers upon one of which a uniform layer ofadhesive of a thickness of about 25 to 50 ,um. is applied by a doctorblade. This adhesive is then transferred from this roller upon theneedle-entry side of the fleece. Before the adhesive dries, the coatedfleece is then compressed, for example, between a pair of revolvingrollers. The method according to the invention may be carried outcontinuously and therefore permits a very economical production of thenew surgical dressmg.

In order to tear apart the thin strips of adhesive which after theadhesive has been applied adhere to and connect many fibers and which,if remaining, might reduce the absorptive capacity of the needledfleece, and since the adhesive accumulates especially at the pointswhere the fibers engage with or intersect each other, the inventionfurther provides that, immediately after the needled fleece leaves thecoating rollers, its coated side he treated with strong jets ofcompressed air.

These and additional features and advantages of the present inventionwill become more clearly apparent from the following detaileddescription thereof which is to be read with reference to theaccompanying drawings, in which FIGURE 1 shows an enlarged crosssectional of a piece of the surgical dressing according to theinvention, while FIGURE 2 shows a top view of the piece of dressingaccording to FIG. 1.

The surgical dressing according to the invention, as illustrated in thedrawings, consists essentially of a needled layer of non-woven fabric orfleece material 1, wherein the uppermost fibers 2 on the needle-entryside 3 are connected to each other by an adhesive coating 4.

The fleece itself consists of cotton and/ or rayon staple fibers asemployed conventionally, for example, for producing absorbent cotton formedical purposes. This fleece 1 is pierced in a needling machineapproximately 150* times per cm. and its structure is thereby changed inthe manner as illustrated in FIGURE 1. It then consists partly of fiberbundles 5 which extend substantially vertically to the longitudinalplane of the fleece 1 and partly of fibers 7 which extend substantiallyparallel to this longitudinal plane. At the points of entry of theneedles of the needling machine, these needles form funnellike recesses6.

After the fleece 1 has left the needling machine, it is passed through apair of revolving rollers, one of which carries a uniform layer of aninert, polymerous, Waterunsoluble elastic adhesive 4 of a thickness ofabout 0.05 mm. which is made on a basis of silicon rubber, celluloseacetate, polyisobutylene or polyamide. This adhesive is transferred bythe coated roller upon the fibers 2 of the uppermost layer of fibers offleece 1 on the: entry side 3 of the needles. In transferring theadhesive 4, the coating rollers should, however, compress the needledfleece 1 only very slightly so as to prevent the lower parts of thefunnellike recesses 6 in the fiber bundles 5 from being clogged byadhesive. The coating operation should therefore be carried out so thatthe adhesive 4 only penetrates into the fibers of the uppermost fiberlayer at the entry side of the needles. After leaving the coatingrollers, the surgical dressing which is thus basically completed istreated by means of strong jets of compressed air so that the smallstrips of adhesive which connect many of the individual fibers to eachother will be torn apart and the adhesive will be deposited primarily onthe points of contact and intersection between the uppermost fibers 2.Before the adhesive 4 dries completely, the dressing material is oncemore compressed between another pair of revolving rollers so that thecoated uppermost fibers 2 will engage with and be glued to each other atadditional points.

By this strong subsequent compression of the dressing material beforethe adhesive 4 has been cured completely, the coated side of thematerial which is to be applied upon the wound is provided with a verysmooth contact surface which may therefore be very easily separated fromthe wound. Furthermore, the adhesive is then no longer capable ofcombining additional fibers, for example, in the funnellike recesses, sothat the absorptive capacity of the needled fleece will not bedimnished. The adhesive 4 of the surgical dressing according to theinvention may, in addition, be provided with a heat-absorbing coloringmatter so that the side of the dressing facing the wound will absorb theheat of the wound and dissipate it to the outer air. The heat which maybe radiated from the outside upon the other side of the dressing will bereflected to the largest extent by the many white fibers. The dressingaccording to the invention will therefore reduce the temperature of thewound considerably.

Before being treated by the needling machine, the fleece 1 may also beapplied upon an additional supporting fabric, for example, absorbentgauze, and thereafter be needled. The light supporting fabric thenprevents the fibers from yielding laterally during the needlingoperation and it solidifies the dressing and maintains its outerdimensions.

Instead of making the dressing of a single thick layer of fleecematerial, it is also possible to employ a plurality of thinnersuper-imposed layers in each of which the fibers preferably extendparallel but at substantially right angles to those in the adjacentlayer. Such a surgical dressing has the advantage of being ofconsiderable solidity and of maintaining its shape and dimensions in alldirections.

Although my invention has been illustrated and described With referenceto the preferred embodiments thereof, I wish to have it understood thatit is in no way limited to the details of such embodiments but iscapable of numerous modifications within the scope of the appendedclaims.

Having thus fully disclosed my invention, what I claim 1. A surgicaldressing of a textile material comprising a needled fiber fleeceincluding an uppermost layer and a coating of adhesive connecting thefibers of the uppermost layer of said fleece to each other at the entryside of the needles into said fleece, adapted to be applied upon awound,

a plurality of the fibers of said fleece extending in a directionsubstantially parallel to its plane,

said fleece being needled in a direction vertical to said plane andforming funnel-like recesses in said entry side,

wick-like fiber bundles extending through said fleece substantiallyvertically to said plane,

said fleece being composed of several layers of straightened fiberssubstantially parallel to and superimposed on each other, and

said fibers of each layer extending at substantially right angles tothose of the adjacent layer.

2. The surgical dressing, as set forth in claim 1, which includes asupporting fabric in said needles fleece.

3. The surgical dressing, as set forth in claim 1, wherein said adhesiveis dyed to receive a heat-absorbent color.

4. A method of producing a surgical dressing of a textile material,comprising the steps of needling a fiber fleece in a direction verticalto its plane,

thereby forming wick-like fiber bundles extending through said fleecesubstantially vertically to said plane and funnel-like recesses in theentry side of said needles into said fleece,

applying a thin coating of adhesive upon said entry side,

in order to cover said side substantially without penetrating into saidrecesses,

applying said adhesive upon said entry side by passing it through a pairof revolving coating rollers to form a thickness of about 50 to ,um.,and then transferred from said roller upon said entry side, andcompressing said coated fiber fleece before said adhesive has dried bypassing it through another pair of rollers pressing upon the oppositesides of said fleece.

5. The method, as set forth in claim 4, which includes the step ofblowing strong jets of compressed air upon the coated side of saidfleece immediately after said fleece leaves said coating rollers andbefore it passes between said compressing rollers.

References Cited UNITED STATES PATENTS 3,292,619 12/1966 Egler 128-1563,301,257 1/1967 Crowe et a1 128-296 3,307,545 3/1967 Surowitz 128-1563,400,188 9/1968 Olson 156-148 ADELE M. EAGER, Primary Examiner US. Cl.X.R.

